Spark-plug



0. ITROVA.

SPARK PLUG.

APPLICATION FILED FEB. 9, 1920.

1,384,413., PatefitedJuly 12,1921.

Z6 I 2/ K? Z7 n /Z V /0 X0 m x 6i; "M 43 If @0622 Z02" dawn/d T ai/aprovide an intensl ,Ewhich may be easily and c eaply produced, l capableof being'readily assembled or taken apart; and to provide aplug havingan airt1 through the center of a 7 improved construction.

UNITED sTArEsPA-rENrorrlce.

OSWALD movaorsr; LOUIS, mssounr, ASSIGNOR, BY nmnc'rnnn lmsim- ASISIGN.mars, or own-114m:- 'ro KING BEE sranx PLUG COMPANY, 01 Sr. LOUIS, MIS-scum, A conrona'rron or mrssounr, AND one-11m Tb rnmi'aenu mnio m 1:.summit, or s'r. LOUIS, mssounr.

SPARK-PLUG.

' To all whom it may Be it known that I OSWALD TROVA, a citizen of theUnited States, residing at St.

Louis, Missouri, have invented a certain new and useful Improvement inSpark-Plugs, of which the following is a full, vclear, and

, exact description, such as will enable others skilled in the art towhich it appertains to make and use the same,- reference being had tothe accompany g drawings, forminglpart of this specification.

y invention relaiiisgenerally to spark plugs, and more particularly to aplug havmg currentcarrying members or electrodes that arev spaced apart.a slight distance to produce a gap that is efiective in intensifymg thesparkthat is'produced between the electrodes at the lower or innerendofthe p The principal objects of my invention are, to generally improveupon and to simplify the construction of the existing types of sparkplugs that have intensifying Ispark gaps; and to provide a relativelysimple and I efiicient construction that is','-under all conditions,self-adjusting in the formation of an intensifying gap, therebywhollyeliminating all manual operations and adjustments necessary to producean effective intenslfy'mg gap Further objects of my invention are, to

g P Sp r P htchamber in whichthe automatically a justable intensifyinggap is located. I With the foregoing and. other objects in view, myinvention consists in certain novel features of construction andarrangement of parts, hereinafter more fully described-and claimed, andillustrated in the accompany-J drawings, in which-- Figure .1 is avertical section taken Fig. 2 is an enlarged verticalsectionitakenthrough the center of the meansmtilized for producing-theself-adjusting intensifym P- v 1g. 3 1s 'a'horizontal section taken onthe line 3-5 of Fig.

Referring bynumerels to the accompany- -lar flange 15 on core 16 :a y

when bushing 12 is screwed t1ghtly 1nto the shell this bushing formsan"- 8.11" tight spark plug of my v Specification of Letters Patent.Patented July 12, 1921,

Application filed February 9, 1920. Serial no. 357,275.

drical shell of metal, the lower portion of which. is externallythreaded as designated by 11 so as to be'inserted into the wall of aninternal combustion engine. .The upper portion of this shell 10 ispreferably enlarged and provided with an internal thread which receivesthe externally threaded lower portionof a metal bush1ng12.

V Inasmuch as the upperportion of the shell 10 is larger than the lowerportion, an internal inclined shoulder 13 is formed between; the upperand lower ortions of said shell and resting upon thls shoulder is agasket Prof-metal or a combination of metal and asbestos and the like,Resting upon this gasket-14- is the underface of anan nular flange- 15that projects outwardly from the central portion of a core 16 ofsuitable insulating material such as "porcelain rnnnnarcx 1 mterminatesadjacent to the inner end of a r radially arranged electrode 18, thelatter being secured to the lowerend of shell '10.

-Theupper end of the core-16;ter'minates 7 in a rounded upwardlypresented "lug 19,

and the upper end of the electrode 17 pro-- 'ects a slight distanceabove the top iof this I lnterposed between the lower end of the 3bushing 12 and the upper faceof the annugasket 20 and joint between thecore 16 and said Fitting snugly the upper. portion of the bushing andsecuredthereto in any Axially disposed in the upper portion of suitablemanner, preferably-by-cement, is a I H this cap insulator is a.substantially c lin-.

drical member 23 of metal in whic Formed integral with and rojectingupwerdly from member 23 is breaded stem is, formed an upwardlyprojecting recess 24.

so engage the lug 19 on the'up' er en'd of. core,

25 and positioned thereupon is a nut 26 and a washer 27, and which partsare effective in anchoring member 23 in thecap insulator. 'The upper endof the threaded stem 25 rei tion of the explosive c ceives the usualterminal receiving: nut 28.

Arranged. to slide freely in the recess 24 is a short cylindricalstem-29, andform'e'd integral with the lower end thereof is an invertedcup-shaped member 30, therounded lower inner edge 31 of which bears uponthe rounded upper face of lug 19, and the space within the chamber 32-between the upper end of electrode 17 and the adjacent surface of theinverted cup-shaped member 30- achieve best results in a device of thiskind,

the width of this intensifying gap should be approximatelyone-thirty-second of an inch, although, of course, this'width may varyaccording to the size of the plug or to the voltage of current utilizedin connection with the ignition system. I

Positioned onstem 29 andinterposed between the cap 30 and the lower endof member 23 is. a relatively light compression spring 33 which acts tohold the rounded lower edge 31 of the cap against the round v ed top ofplug 19.

pare lugs 35. l

j has considerable. vertical movement and;

To retain the stem 29 in sliding engage ment with member 23, the upperportion of stem 29 is provided with an annular groove 351 ofconsiderable width and projecting into said groove fromthe. wall ofmember 23 It frequently happens that through im L perfect manufacture=or distortion while baking, the coreinsulators 16 are not '-al-.' waysuniform in size and shape and .as aresult, it is practically impossibleto reduce the desired and effective spark gap y man ual adjustment ofparts, but in myimproved construction, the spring-pressed member 29while the bushing 12 carrying cap insulator and'parts associatedtherewith is screwed into the upper end of shell -10,fith e cap 30'carried by the lower endof member29 lWill insulator 16 and automatieal yad'ust itself so asto form the des'ired'and e ec'tive in-- tensifyinggap.v The inverted cup-shaped member 30 cooperates with lug 19 informing, under all conditions, a universal j-oint,

" and which arrangement is effective in-pro- 'ducing without manualmanipulation or adgap is efi'ective'inintensifying firing spark trodes,one of w of the nitrogen and oxygen in the air Within chamber 22 will beconsumed by the sparkv i produced at the intensifying gap within saidchamber and as a result of this absence of atmospheric. resistance, theefliciency of the device in operation is ,materially 1n-' creased.

It will be readily understood that minor changesin the size,'formandconstruction of the various parts of. my improved spark plug can bemade and sub tituted for those herein shown ali describe ,withoutdparting from the spirit "of myinvention, the scope of which is claims.

I claim f. In a spark plug, ia shell, an insulating core positionedtherein, an electrode extending through said core, a "cap insulator in-.closing the upper portion of said insulating core, and a selfadjusting'electrode car-' riedrby said cap insulator and'adapted to.

bear upon the upperportion ofthe insulat set forth inthe appended ingcore whereby an intensifying spark gap is formed betweensaidself-adjusting electrode and the electrode that-.extendsthrough,saidcorer, H

'2, In'asparkfplug', a shell, an insulating core positioned therein, anelectrode 'extending through and projecting beyond .the-up,.

per end of'said ogre," acap insulator in; closing the upper portlon'ofsaid insulating core and the projecting terminal of the elee trodeextending-itherethrough,.and a spring;-

pressed electrode carried by said'cap 111 t lator, andadapted-to bear'upon the upper portion of theiinsulatinge core around said.

projecting end of said electrode, whereby a spark gap is formed betweensaids'prii g tends through said core.

spaced relation tof-fo'rm "an intensifying gap of el trod pressedelectrode and the electrode which X-z.

and a spring associated with one of said.

electrodes? and tending to normally force. ittoward the other electrode.H '4. In} a spark plug, a pair of electrodes,

means, for maintaining said electrodes in spaced "relation tofonfianintensifyin gap,

and a spring associated lwith one 0 said electrodes and tending tonormally force it itoward the other electrode, the end of saidspring-pressed electrode partially inclosing theadjacent end ofthe otherelectrode.

- 5. In a spark plug], a pairofspac'ed elec- 10 1s spring-"pressed to;

ward the other, and means for maintaining said electrodes in spacedrelation.

6. In a spark plug, a pair of spaced electrodes, one of whichisspring-pressed toward the other, and provided with a recess whichreceives the adjacent end of the opposite electrode, and means formaintaining said electrodes in proper spaced relation.

7. In a spark plug, a shell, a core insu' lator positioned therein, abushing removably connected to said shell, a cap insulator carriedbysaid bushing, there being an airtight chamber formed between the coreinsulator, the bushing, and the cap insulator, electrodes carried by thecore and cap insulators, the adjacent ends of which electrodes terminatewithin the air-tight cham: ber, means for maintaining said electrodes inspaced relation, and a portion of one of said electrodes beingspring-pressed toward the other.

.end of the other electrode.

9. In a spark plug, a shell, a core insulator positioned therein, abushing removably seated in the shell, a cap insulator carried by saidbushing, an electrode passing through the core insulator, an electrodepassing through the cap insulator, a portion of which last mentionedelectrode is springpressed and normallybears on the upper portion of thecore insulator to maintain the electrodes in spaced relation and form anintensifying spark gap.

10. In a sparkplug, a pair of insulators, electrodes passingtherethrough, and a spring-pressed member forming a part of one of saidelectrodes, the end of which spring-pressed member bears on the end ofthe insulator carrying the opposite electrode to maintain the electrodesin spaced relation and thereby form an intensifying spark gap and theterminal portion of said springpressed member partially surrounding theprojecting end of the end portion of the opposite electrode.

In testimony whereof I hereunto afiix my signature this 3d day of Februa 1920.

OSWALD ROVA.

